| /* |
| * Copyright (C) 2010, Google Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND |
| * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE |
| * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
| * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH |
| * DAMAGE. |
| */ |
| |
| #ifndef THIRD_PARTY_BLINK_RENDERER_MODULES_WEBAUDIO_REALTIME_ANALYSER_H_ |
| #define THIRD_PARTY_BLINK_RENDERER_MODULES_WEBAUDIO_REALTIME_ANALYSER_H_ |
| |
| #include <atomic> |
| #include <memory> |
| |
| #include "base/macros.h" |
| #include "third_party/blink/renderer/core/typed_arrays/dom_typed_array.h" |
| #include "third_party/blink/renderer/platform/audio/audio_array.h" |
| #include "third_party/blink/renderer/platform/audio/fft_frame.h" |
| |
| namespace blink { |
| |
| class AudioBus; |
| |
| class RealtimeAnalyser final { |
| DISALLOW_NEW(); |
| |
| public: |
| RealtimeAnalyser(); |
| |
| uint32_t FftSize() const { return fft_size_; } |
| bool SetFftSize(uint32_t); |
| |
| unsigned FrequencyBinCount() const { return fft_size_ / 2; } |
| |
| void SetMinDecibels(double k) { min_decibels_ = k; } |
| double MinDecibels() const { return min_decibels_; } |
| |
| void SetMaxDecibels(double k) { max_decibels_ = k; } |
| double MaxDecibels() const { return max_decibels_; } |
| |
| void SetSmoothingTimeConstant(double k) { smoothing_time_constant_ = k; } |
| double SmoothingTimeConstant() const { return smoothing_time_constant_; } |
| |
| void GetFloatFrequencyData(DOMFloat32Array*, double); |
| void GetByteFrequencyData(DOMUint8Array*, double); |
| void GetFloatTimeDomainData(DOMFloat32Array*); |
| void GetByteTimeDomainData(DOMUint8Array*); |
| |
| // The audio thread writes input data here. |
| void WriteInput(AudioBus*, uint32_t frames_to_process); |
| |
| static const double kDefaultSmoothingTimeConstant; |
| static const double kDefaultMinDecibels; |
| static const double kDefaultMaxDecibels; |
| |
| static const unsigned kDefaultFFTSize; |
| static const unsigned kMinFFTSize; |
| static const unsigned kMaxFFTSize; |
| static const unsigned kInputBufferSize; |
| |
| private: |
| // The audio thread writes the input audio here. |
| AudioFloatArray input_buffer_; |
| std::atomic_uint write_index_{0}; |
| |
| unsigned GetWriteIndex() const { |
| return write_index_.load(std::memory_order_acquire); |
| } |
| void SetWriteIndex(unsigned new_index) { |
| write_index_.store(new_index, std::memory_order_release); |
| } |
| |
| // Input audio is downmixed to this bus before copying to m_inputBuffer. |
| scoped_refptr<AudioBus> down_mix_bus_; |
| |
| uint32_t fft_size_; |
| std::unique_ptr<FFTFrame> analysis_frame_; |
| void DoFFTAnalysis(); |
| |
| // Convert the contents of magnitudeBuffer to byte values, saving the result |
| // in |destination|. |
| void ConvertToByteData(DOMUint8Array* destination); |
| |
| // Convert magnidue buffer to dB, saving the result in |destination| |
| void ConvertFloatToDb(DOMFloat32Array* destination); |
| |
| // doFFTAnalysis() stores the floating-point magnitude analysis data here. |
| AudioFloatArray magnitude_buffer_; |
| AudioFloatArray& MagnitudeBuffer() { return magnitude_buffer_; } |
| |
| // A value between 0 and 1 which averages the previous version of |
| // m_magnitudeBuffer with the current analysis magnitude data. |
| double smoothing_time_constant_; |
| |
| // The range used when converting when using getByteFrequencyData(). |
| double min_decibels_; |
| double max_decibels_; |
| |
| // Time at which the FFT was last computed. |
| double last_analysis_time_; |
| |
| DISALLOW_COPY_AND_ASSIGN(RealtimeAnalyser); |
| }; |
| |
| } // namespace blink |
| |
| #endif // THIRD_PARTY_BLINK_RENDERER_MODULES_WEBAUDIO_REALTIME_ANALYSER_H_ |